The invention relates to an air supply apparatus for use in a fuel cell system, and more specifically to such apparatus for a fuel cell system of the type which is suitable for stable operation under servere conditions of sharp fluctuation of load or air pressure being supplied.
Concerning conventional air supply apparatus for a fuel cell system, it has typically been discussed in a technical literature entitled "Specification for Dispersed Fuel Cell Generator", one of the technological reports of electric Power Research Institute (EPRI) in America.
Generally, the air supply apparatus for a fuel cell system serves to supply air to a cell cathode of the fuel cell system and a combustion section of the reformer unit while effecting recovery of energy possessed by exhaust air from the cell cathode and exhaust gas from the combustion section of the reformer unit.
With such conventional apparatus for air supply applied to a fuel cell system wherein severe load fluctuation tends to occur, there has been involved the following disadvantages.
a. Due to sudden load changes, there may occur fluctuation of air or fuel supply pressure. This tends to cause unstable combustion, blowing-out of burning flames, etc. PA0 b. When operating under a partial load, the flow rate of fuel or air passing through the fuel nozzle or the air nozzle, respectively, will be reduced so that its velocity of flow is decreased beyond a design limit. This tends to incur unstable combustion, blowing-out of burning flames, etc. PA0 c. Due to elevated temperatures of combustion, there may be provided a significantly large amount of nitrogen oxide (NO.sub.x) PA0 d. Since the apparatus inherently incorporates those parts for ignition or pilot, there may arise the extra necessity of maintaining high reliabilities of those accessory parts for safety.